Posts tagged with "Current Biology"

Can’t stop those toes from tapping? Just want to boogie down? You have company: A Harvard study of YouTube sensation Snowball, the dancing cockatoo, spotlights the surprising variety and creativity of his moves and suggests that he, and some other vocal-learning animals, may be capable of some of the kind of sophisticated brain function thought to be exclusively human.

The white bird with the yellow-crested head became an Internet sensation in 2009 when videos of him grooving in perfect time to Another One Bites the Dust” by the British rock band Queen went viral. To date, 7.3 million people have clicked on the three-and-a-half-minute clip and millions more have watched videos of the bird bouncing and bobbing to chart-toppers by Michael Jackson and the Back Street Boys.

“He predicted the timing of the beat, and he did this spontaneously without having been trained,” said Patel, whose 2009 findings were similar to those reported by Harvard researchers that same year involving the African grey parrot Alex and his ability to match his movements to the beats of novel songs.

In the paper, Patel and his team list the five traits they believe are required for an animal to be able to spontaneously dance to music: vocal learning; the ability to imitate; a propensity to form long-term social bonds; the ability to learn a complex sequence of movement; and an attentiveness to communicative movements. Humans and parrots share all five.

“We think these five together in an animal brain lay the foundation for an impulse to dance to music with diverse movements,” said Patel, who noted other animals can do some of the five things but not others. Monkeys, for example, can imitate movements but have very limited vocal learning capacity, he said, and thus can’t move rhythmically to music. “It’s unusual for all five things to come together, and when they do it means a brain is primed to develop dancing behavior if it’s given exposure to music with rhythm and beat.”

The researchers filmed Snowball dancing to the songs, then coded his individual movements. In order to qualify as a distinct move, the parrot had to repeat it at least two times at different points in the study.

The report’s lead author, R. Joanne Jao Keehn, a cognitive neuroscientist and a trained dancer, analyzed the videos frame by frame and labeled Snowball’s different motions. She found that among the bird’s favorite steps are the “Vogue,” the movement of his head from one side of his lifted foot to another; the “Headbang with Lifted Foot,” when he lifts his foot and bangs his head simultaneously; and the “Head-Foot Sync,” during which he moves his head and foot in unison.

In addition to being wildly entertaining, the bird’s variety of movements point to a type of cerebral flexibility that suggests his creative choreography is not simply “a brainstem reflex to sound,” said Patel. “It’s actually a complex cognitive act that involves choosing among different types of possible movement options. It’s exactly how we think of human dancing.”

Wake up, America! A study conducted at the University of Colorado–Boulder has found that trying to catch up on shut-eye over the weekend may not be such a good idea—for either your waistline or your health, CNN reported on February 28.

Study author Kenneth Wright, Jr., who directs the Sleep Lab at the UC-Boulder, agrees. “Sleeping in on weekend doesn’t correct the body’s inability to regulate blood sugar, if that weekend is followed by a workweek or [a]school week full of insufficient sleep,” he told CNN.

The study by Wright and his colleagues—published in the journal Current Biology—assigned 36 healthy young men and women to three groups that prescribed different sleep requirements over a total of 10 days. None of the participants had newborns in the home or any health impairments that would affect the quality of their sleep.

That could be in part, Polotsky told the news outlet, because hunger hormones are affected by a chronic lack of sleep. “The hormone leptin decreases appetite, while the hormone ghrelin increases appetite,” explained Polotsky, who was not involved in the study. “We know from previous research that sleep deprivation causes leptin to drop and ghrelin to rise, so you’re hungry.”

Why? One of the reasons the weekend group may have been more affected is because their circadian rhythm, or biological clock, had been altered, depriving the body of certain hormones.

“If you catch up during weekends, you habitually eat later, because the circadian clock is shifting,” Polotsky said. “Add in after-dinner snacks; the sleep-deprived eat much more after dinner, as well.”

“That helps us understand why is it that when we don’t get enough sleep, we have an increased risk for things like diabetes,” he added, because “short, insufficient sleep schedules will lead to an inability to regulate blood sugar and increases the risk of metabolic disease in the long term.”

Metabolic syndrome is an array of symptoms such as fat around the waist, abnormal cholesterol, high blood sugar, and high blood pressure—all of which can raise the risk of heart disease, stroke and diabetes.

“And when we go back to getting too little sleep again,” Wright told CNN, “we’re doing things that could be negative for our health long-term.”

Do you ever feel as if you have been singled out in a crowd—the only one to return home from outdoor activities with itchy, red welts rising all over your body? Well, we hate to say so, but it’s true: Mosquitos remember the taste and smell of human blood, according to researchers at the Frain Life Science Institute atVirginia Tech, and they often pick on people whose blood tastes the sweetest to them.

That’s the bad news. The good news, based on a recent study, is that, if you swat determinedly at the mosquitoes around you, they will remember the unpleasant sensation—and stay away from you in the future.

Indeed, the Virginia Tech study—published last January in the journal Current Biology—found that the pesky insects have much larger and longer memories than we could have imagined. The researchers found that mosquitoes can learn rapidly and remember the smells of the tastiest hosts. Dopamine is a key mediator of this process. Mosquitoes use this information and incorporate it with other stimuli to develop preferences for a particular vertebrate host species, and, within that population, certain individuals

However, the study also proved that even if an individual is deemed delicious-smelling, a mosquito’s preference can shift if that person’s smell is associated with an unpleasant sensation. Hosts who swat at mosquitoes or perform other defensive behaviors may be abandoned, no matter how sweet.

Twenty-four hours later, the same mosquitoes were assessed in a Y-maze olfactometer in which they had to fly upwind and choose between the once-preferred human body odor and a control odor. The mosquitoes avoided the human body odor—suggesting that they had been successfully trained.

By taking a multidisciplinary approach and using cutting-edge techniques, including CRISPR gene editingand RNA interference (RNAi), the scientists also were able to identify that dopamine is a key mediator of aversive learning in mosquitoes.

They targeted specific parts of the brain involved in olfactory integration by fitting mosquitoes with helmets that allowed for brain activity recordings and observations. By placing mosquitoes in an insect flight simulator and exposing the mosquitoes to various smells, including human body odors, the scientists observed how the insects, trained or not, reacted. What they saw is that the neural activity in the brain region where olfactory information is processed was modulated by dopamine in such a way that odors were easier to discriminate, and potentially learn, by the mosquitoes.

“Unfortunately, there is no way of knowing exactly what attracts a mosquito to a particular human. Individuals are made up of unique molecular cocktails that include combinations of more than 400 chemicals,” said Lahondère. “However, we now know that mosquitoes are able to learn odors emitted by their host and avoid those that were more defensive.”

“Understanding these mechanisms of mosquito learning and preferences may provide new tools for mosquito control,” said Vinauger. “For example, we could target mosquitoes’ ability to learn and either impair it or exploit it to our advantage.”